Background ;
Previous study showed that coronary flow velocity is useful method to evaluate microvascular impairment in acute myocardial infarction. However the value of coronary flow velocity using Doppler echocardiography has not been established in prediction of LV remodeling after successfully reperfused STEMI especially compared with 18-F FDG PET.
Method
27 patients who had their first anterior STEMI and were successfully reperfused by primary PCI and confirmed patent infarct related artery by 8months follow up coronary angiography were enrolled this study. Measuring coronary flow velocity profile by Doppler echocardiography was performed at 2 and 5 days after Primary PCI, respectively. Myocardial viability in the LAD region was measured by 18-FDG PET at 14 days after Primary PCI. In F-18 FDG PET study, non-viable myocardium was defined as below 40% of maximal FDG uptake in the non-infarcted myocardium. Follow up echocardiography was done at 8months later. LV remodeling index was defined as LV end diastolic volume change (%).
Result
Diastolic deceleration time (DDT; r=-0.504, p=0.006) and diastolic deceleration rate (DDR; r=0.584, p=0.001) measured at 5 days after PCI, non-viable myocardium area quantified by PET (r=0.510, p=0.010) were significantly correlated with increase of remodeling index. However, coronary flow velocity profiles at 2days after reperfusion did not show significant correlation with remodeling. In multivariate linear logistic regression analysis, DDT (HR -2.10, 95% CI -0.036 - -4.503, p=0.047) and DDR (HR 2.058, 95% CI 0.001-0.095) at 5 days after PCI were independent predictive factors of LV remodeling. However, non-viable myocardium area by PET could not predict LV remodeling
Conclusion
Coronary flow profile at 5 days after Primary PCI is simple and useful tool to predict long term LV remodeling.